Video conferencing allows conference participants who are at different locations to participate in a conference. Typically, each conference participant has a computer-based video conferencing system that includes a video camera, a microphone, a display device, and a speaker. The video conferencing system of a conference participant captures the video and audio of that conference participant using the video camera and microphone and transmits the video and audio to the video conferencing systems of the other conference participants. When a video conferencing system receives the video and audio from the other conference participants, it presents the video on the display device and outputs the audio to the speaker. A video conferencing system may display each video in a different window on the display device. Thus, the conference participants can view the video and hear the audio of the other conference participants.
Most video conferencing systems simply tile the windows on the display device. For example, each window may be the same size and arranged in a left-to-right, top-to-bottom manner. Some video conferencing systems allow a conference participant to rearrange and resize the windows. For example, a conference participant may arrange the windows so that the video of the conference leader is in the center of the display and the videos of the other conference participants surround the video of the conference leader.
One video conferencing system displays the windows of the videos in a “perspective” view. This perspective view allows the video of one window to be displayed as the focal point and the videos of other windows to be displayed either on the periphery or as a minimal window. FIG. 1 is a diagram that illustrates the perspective view of a video conference. The video conferencing system displays four windows 101-104 on the display 100. Window 101 is displayed as the focal point of the video conference, windows 102 and 103 are displayed on the periphery, and window 104 is displayed as a minimal window. The video of window 101 may be of the conference leader and thus is shown as the focal point of the video conference. Windows 102 and 103 are shown on the periphery of the focal point to provide the illusion of a perspective view leading to the focal point.
Although the video conferencing systems allow a conference participant flexibility in arranging windows, the process of arranging the windows can be time-consuming. As a result, a conference participant will typically only arrange the windows at the beginning of a video conference. A conference participant may position the window of the conference leader in a prominent or primary location on the display and the windows of the other conference participants in a secondary location on the display. If, however, the conference leader is not the primary speaker at the conference, then the conference participant may need to focus on a window at a secondary location or rearrange the windows during the conference. It would be desirable to have a video conferencing system that would automatically and dynamically display prominently the video of the conference participant who is currently speaking. It would also be desirable to display the video of other conference participants who are not currently speaking less prominently.